docs: def validate_otp(hsm, from_key):
      """
      Try to validate an OTP from a YubiKey using the internal database
      on the YubiHSM.
  
      `from_key' is the modhex encoded string emitted when you press the
      button on your YubiKey.
  
      Will only return on succesfull validation. All failures will result
      in an L{pyhsm.exception.YHSM_CommandFailed}.
  
      @param hsm: The YHSM instance
      @param from_key: The OTP from a YubiKey (in modhex)
      @type hsm: L{pyhsm.YHSM}
      @type from_key: string
  
      @returns: validation response, if successful
      @rtype: L{YHSM_ValidationResult}
  
      @see: L{pyhsm.db_cmd.YHSM_Cmd_DB_Validate_OTP.parse_result}
      """
      public_id, otp = split_id_otp(from_key)
      return hsm.db_validate_yubikey_otp(modhex_decode(public_id).decode('hex'),
                                         modhex_decode(otp).decode('hex')
                                         )